Insulation Systems: Inspection and Maintenance

June 1, 2014

Insulation systems, like all mechanical systems, require periodic inspection and maintenance. While inspection and maintenance are the responsibility of the owner, the fact is that many insulation systems are frequently ignored. With time, insulation systems can be damaged, and if they are not repaired or replaced, they can become ineffective. Insulation contractors can play a key role in facilitating regular inspection and maintenance programs to prevent this outcome. Failure to perform inspections and implement a timely maintenance plan carries a number of risks. On hot systems, missing insulation results in increased heat loss, which may translate to significant economic losses over time. For outdoor systems, damaged or missing weather barriers can allow rainwater entry, which can compromise the effectiveness of the insulation system. On cold systems, damaged vapor retarders will lead to increased water vapor intrusion, which can reduce insulation effectiveness, increase rates of corrosion, and increase the potential for mold growth. If an inspection reveals missing or damaged insulation, repairs should be scheduled as soon as possible. This is particularly true for cold systems, where water vapor intrusion can rapidly spread.

At a minimum, insulated areas should be inspected annually. Inspection of the external surface should include checking for signs of cracking, distortion, damage, or corrosion; evidence of hot spots on high-temperature systems; and condensation and ice buildup on low-temperature systems. When necessary, external finish should be removed to enable inspection of the insulation and attachments. Infrared video cameras have been found to be useful for inspection and should be considered for use after the start-up inspection and for ongoing insulation maintenance.

When removal and replacement is indicated, re-insulation should be performed in the same manner as the original installation unless the nature of the damage indicates that the system was improperly insulated or the materials originally used are now outdated. Damaged insulation should be torn back to undamaged material. Care should be taken in removal of existing insulation to minimize damage. Temporary protection for adjacent insulation may be required to prevent damage while repairs are underway.

The following “Risk Assessment Discussion” and “Maintenance Check List” have been designed by the National Insulation Association (NIA) along with the National Mechanical Insulation Committee for mechanical insulation applications as defined in the National Institute of Building Sciences’ (NIBS’) Mechanical Insulation Design Guide (MIDG).

Risk Assessment Discussion
There are risks associated with not maintaining a mechanical insulation system in a timely and effective manner. Those risks and the severity of potential consequences will vary depending upon the use/service temperature of the operating system on which the insulation is installed, the surrounding environment, ambient conditions, the extent of any damage to the insulation system, the insulation system design, quality of the installation, the timeline of correcting any damage, and other occurrences that may be unique to the area in question.

The following list depicts the type of risk that could occur if you fail to implement a timely and effective mechanical insulation maintenance plan. However, as previously mentioned, they may not apply to all situations, and may occur separately or simultaneously:

  1. Increase in energy costs
  2. Increase in greenhouse gas emissions
  3. Loss of process/production quality and increase in costs
  4. Occurrence of corrosion under insulation
  5. Development of condensation or ice, depending upon the service temperature
  6. Development of mold or mildew
  7. Decrease in personnel safety
  8. Decrease in personnel productivity
  9. Loss of time spent on other projects
  10. Decline in facility appearance
  11. Decrease in the life and operational efficiency of equipment in the area
  12. Increase in “life-cycle” cost
  13. Failure to obtain sustainability objectives
  14. Failure to obtain return on investment estimates

Each company and individual has their own level of risk tolerance; however, the risk of failing to establish a timely and proper mechanical insulation maintenance plan is real and should not be overlooked or underestimated.

“Maintenance Check List”
Upon observing any of the following conditions, a maintenance request/action plan should be implemented to assess the degree of damage, and the damaged area of the insulation system should be repaired or replaced to prevent further damage and to avoid further risk. The listing does not appear in order of importance or priority. The Check List is provided as a simple guide for individuals evaluating the condition of an installed mechanical insulation system. It is not intended to be all inclusive or to provide sufficient information to act as a stand-alone document that would allow anyone, experienced or inexperienced, to function as an inspector of mechanical insulation systems.

Checking for all of the following occurrences is a good start for a maintenance plan:

  • Damage to or wearing of the outer jacketing/finish of the insulation system (damage could be caused by mechanical abuse, negligence, or weather; or it could simply occur over time)
  • Unsealed penetrations in the insulation system
  • Missing insulation
  • Insulation that has been removed and not yet replaced
  • Insulation supports that are failing or appear not to be working correctly
  • Ice, mold, mildew on/in the insulation system
  • Condensation
  • Discoloration of the insulation system, other than by dirt
  • “Fish mouthing” of the outer jacketing seams
  • Missing or loosening of insulation system securements
  • Sagging or pulling away of the insulation system
  • “Hot spots” in the insulation system
  • Appearance of moisture on the insulation system
  • Joints in the insulation that appear to be opening
  • Expansion or contraction joints that appear to be functioning incorrectly
  • Insulation system being used in an environment or service that is different from the original design for the insulation system

With proper attention and maintenance, insulation systems can save a company considerable energy and money over time, and improve process efficiency and equipment life. Mechanical engineers and insulation contractors can play a key role in facilitating regular inspection and maintenance programs to achieve this outcome.